package thread;

import java.util.ArrayList;

public class Test {
    public static void main(String[] args)throws InterruptedException{
        ArrayList<Integer> list = new ArrayList<>();
        Thread t1=new Thread(){
            public void run(){
                for(int i=0;i<10000;i++){
                    synchronized (list){
                        list.add(i);
                    }

                }
            }
        };
        Thread t2=new Thread(){
            public void run(){
                for(int i=0;i<10000;i++){
                    synchronized (list) {
                        list.add(i);
                    }
                }
            }
        };
        t1.start();
        t2.start();
        Thread.sleep(1000);

        System.out.println(list.size());

    }
}
